MonkeezOnFire
Adventurer
And yes, it stacks with PAM and GWM, which is of concern. However at some point or another a non-fighter is spreading themselves thin: It takes 4 ASI to max the attack stat and Int, plus an ASI to take the feat, so a normal class has already used all of theirs.
My concern is that with enough feats granting bonus damage that characters won't have a reason to increase their attack stat, which feels off. The attack stat increases damage and accuracy, but accuracy isn't a huge issue because a) it also scales with proficiency and b) there are so many ways to increase accuracy through spells, accuracy or other class features.
The eldritch knight and arcane trickster especially have many ways to grant advantage, the biggest being a familiar spamming the help action. And since they already have a reason to bump int, int just becomes their primary stat.